Model Diagnostic Discussion
NWS Weather Prediction Center College Park MD
229 AM EDT Sat Apr 07 2018

Valid Apr 07/0000 UTC thru Apr 10/1200 UTC

...See NOUS42 KWNO (ADMNFD) for the status of the upper air
ingest...

00Z model preferences with confidence intervals
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NAM/GFS initialization errors do not seem to degrade their short
range forecasts.


System approaching the West Coast on Monday night
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The guidance shows some timing issues offshore, but nothing that
impacts the lower 48 through 84 hours/Tuesday morning.   A
compromise of the 00z GFS, 00z NAM, 00z ECMWF, 00z UKMET, and 00z
Canadian is preferred with above average confidence.


Trough digging into the Midwest Tuesday morning
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Preference: GFS/ECMWF/UKMET blend; confidence above average

The 00z NAM is sharper and somewhat quicker with its trough
progression which leads to a more northerly surface low near the
NC coast.  The NAM is north of the entire 12z global ensemble
envelope at the surface, so believe it to be a low probability
alternative scenario.  The 00z Canadian was a hair sharper than
the other guidance -- its usual bias -- with this system which
leads to a somewhat different precipitation scenario for the Lower
Rio Grande and central Plains.  A compromise of the 00z GFS, 00z
ECMWF, 00z UKMET is preferred with above average confidence.  See
our Quantitative Precipitation Forecast discussion for more
details on precipitation preferences.


Trough moving out of New England Sunday
Shortwave moving through the Southeast Saturday
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The guidance shows reasonably good agreement with these systems. 
A compromise of the 00z GFS, 00z NAM, 00z ECMWF, 00z UKMET, and
00z Canadian is preferred with above average confidence.


Model trends at www.wpc.ncep.noaa.gov/html/model2.shtml
500 mb forecasts at www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml

Roth